Mandible fractures are usually caused by trauma to the lower face. This will cause pain in the jaw and can sometimes cause the occlusion of your bite to be off. The repair of the fracture
depends on how your brother broke his jaw and if his occlusion is off. It will ultimately be up to the physician that is taking care of your brother as to how he will repair the fracture. You should discuss these questions with him.
There are different types of fractures of the mandible. Sometimes mandible fractures can be treated with just a soft diet and pain control. Sometimes they will require open reduction internal fixation, which means that he will go to surgery
and they will find the area of the fracture. Sometimes the fracture will require a plate with screws to hold the plate in place to reapproximate the fracture. Occasionally patients will also require MMF which means they have to have their teeth wired together in order to fix their bite to make sure that it goes back to baseline.
It is important that you discuss these questions with the physician that is taking care of your brother. He will decide the best way to fix your brother's jaw fracture.